We often talk about snails (蜗牛) and their slow move. But usually snails don't move at all. They are in their shells (壳)—sleeping.
Hot sun will dry out(使变干)a snail's body. So when it is very hot, a snail draws its body into its shell. A snail will die in a heavy rain. So when it rains, a snail does the same thing, too. A snail can sleep for a long time. It spends all the winter in its shell, sleeping.
In spring, the snail wakes up(醒来). Its body is only about
0. 07 meter long out of the shell. When hungry, the snail looks for food. Its eyes are not very good. But it does very well in smell(嗅觉). This helps the snail to find food and the new plants.
A snail's mouth is no bigger than a full stop (句号). But it has 25,600 teeth! The teeth are very small, and you can't see them. If you put a snail in a paper box, it will eat the box and find its way out! And if its teeth are too old, it will grow new ones.